66 MEMORANDA. 



the light is reliectcd from the inner edge of each oblong 

 foramen, and in several broken pieces the line of fracture 

 is invariably through the depressions. Thus from analogy 

 we derive our convictions. There is also collateral evidence 

 — in the same slide there are some pieces near the edge 

 that have been accidentally placed in contact Avith thick 

 balsam, and the fluid has been found to enter the pores by 

 capillary attraction, Avhich it "would not have done had they 

 been elevations. But I am perhaps scarcely qualified to 

 form a conclusion ; but I have laid before you the premises 

 upon which I have founded my conclusion, and I shall be 

 very glad to send you the slide for your inspection, if you 

 wish. My sole object in troubling you Avas to show the wide 

 geographical range of this species, the one being derived 

 from the North Sea, the other from the West Coast of 

 Africa, and also the age of the species, as I presume that 

 described by Mr. Norman to be a recent species, mine is 

 fossil.— W. r. Cooper, Sheffield. 



